Ygduf

I guess you could, but that would change the angle of the stay at the hub, right? I dunno. It's weird and if this turns out to be some weird old hub that saves 2w at 30mph but is 2mm narrower than standard, that's pretty negligent to keep putting it back on the kid's bike.

wens

I mean, I want to see somebody draw a free body diagram of how a wheel gets driven out. Maybe cocked enough to brake rub/rub the chainstay, but I've never even heard of a rear wheel falling out from sprinting before this thread.

To my original point, the forces in the wheel should be pulling it up into the drop out. It's not like we're talking track wheels that can move in the same direction as the force from the chain.

hack

I can't really say how it happened to me, but it did. It was right after a hard jump for a 200m sprint. First two pedal strokes were solid then the rear just felt wobbly and soft. I coasted until the others riders came past and checked it out. The rear skewer was really loose (even though it had been tightened that morning) and the wheel was kind of just floating in the drop out. I cinched it down to what felt like normal, check it periodically, but haven't had an issue since. Maybe something happened earlier in the day or the quick release got hit and I didn't know it ... dunno, but it wasn't a fun experience.

Ygduf

it's the crazy junior sprint where the bike swings 60 degrees in an arc, side to side. As the rider weights the left foot, the juniors bike is 30 degrees tilted to the right. That creates a fulcrum of down force on the left side of the hub, and the tire provides a sideways resistance that causes the right side of the hub to pop out, especially if it's some non-normal hub or the skewer is loose.

spectastic

you don't need a diagram. just loosen the skewer, lift the wheel, turn the crank, and watch that sucker jump out.

tetonrider

it wouldn't change the angle in any material way. you're basically making it 1mm or so wider--chainstays are >400mm.

anyway, it is weird to *need* to do it.

i'm confused by this whole thread, but i thought this was some weightweenie hub from when his kid was 70 pounds???

agreed on negligence suspicion.

Ygduf

but if you wanted one

spdntrxi

dynamics... oh so fond memories... not, I barely passed.

Doge

Cav is 148lbs - same size as my kid - was (he is lighter now). Cav publishes his power after riding some 100+ miles with a high 30mph sprint. These are totally different disciplines, I doubt my kid would be able to make the finish.
Most every track sprinter is faster with more power than Daniel. Most every pro tour rider is not. Look at other sports and check out teen power and strength. They (the pro tour riders) know this inc. Sagan, Cav and others Daniel has ridden with. If it makes you feel better there are many USA crit riders more powerful than Cav and Daniel, they just can't finish the distance Cav does and cannot handle the speed. It is not a valid comparison.

Last month Daniel was gapped at Paris Roubaix and had to close it with a time that matched Niki Terpstra KOM time bridging back on - a pro level "KOM" 30+ mph in Paris Roubaix. There was no power meter. His finish was the best 17 year old USA finish ever. It is totally valid that he is stronger and faster than a guy riding some 100+ miles. Winning races and being the most powerful rider at the end are different. This was about pulling a wheel out, but the power numbers are real.

Here is a repost of a video last year vs. a Cannondale tour pro, the current SoCal Cat 1 champ, a few USA team U23 riders on the same wheels - different frame. https://vimeo.com/113856699

spectastic

shouldn't all the arrows cancel out? according to this diagram, this rider is accelerating to the left. and a more helpful diagram would be one that actually shows the vertical forces.

who ever drew this gets a big fat F

Doge

Its a Extralite hub got it 2 years ago.

Doge

They are not pulling into the dropout. Bike upside down the wheel jumps out spinning crank. I believe you notice @hack and others having similar issues. Turns out some other (not BF posters) have too.

spdntrxi

I thought the sticker looked familiar.. I use a weightweenie extralite hub as well...a new one, but I doubt it matters. I think the highest wattage I've hit is around 1100 with it.. no issues so far. Enve skewers.. parlee frame.

Doge

We need to establish what the problem is. Other than two, same wheel, every sprint last two years. He has not lost one where he had open road. Is it negligent to use the Venge?

https://vimeo.com/117212534

spectastic

am I understanding this correctly? your son got invited to the paris roubaix.......

Doge

Correct. Juniors.

spectastic

that's so cool. with the development team?

Doge

Team USA
Just that :
Shows who is not paying attention.

Anyway - his wheel was pulling out, I want to fix it and Cav's setup may not do it.

spectastic

call me sally, team USA?? so he's racing as a pro?

and I think that dropout may be a manufacturing defect. the only reason I can think of for why the wheel would slide out is that the steel dropout was not properly bonded to the carbon. and because that interface between the carbon and metal dropout surface doesn't have the grooves that you find on the skewers, that would be the weak link that ends up breaking apart. I think the skewer was tight enough for it to not move, but your picture indicates that it was the dropout that gave away. I would call specialized about it.

hack

Boonen must put out some power on his Venge, what's he running for wheels/hubs/skewers?

spectastic

damn those german geneticists!

Doge

These pros (Boonen) ARE NOT putting out the peak power of domo crit riders and certainly not track sprinter. Their average power is higher - different game.

Anyway I just asked junior - if it came down to it trade wheels or Venge. He said Venge.

Doge

No - Team USA juniors. Not pro.

Yes - calling Specialized. That @hack had issues is also important data point. I posted here for ideas and feedback. Seems it happens a bit.

spectastic

cat 1? how do they make the selection for the team?

Doge

Team USA is juniors 17-18, U23 and then Olympics.
Cat does not matter. Winning certain junior races does. Politics seems to. Winning some adult races matters too - but less.

The top junior races are more competitive than the Cat 1 races. VOS, Sea Otter and National top riders normally have a few Cat 2/Cat 1 wins. For juniors there is no mandatory upgrade. Kids sit on their upgrade points. Daniel had triple what he needed before going to Cat 2, Gage maybe quadruple. Adrian chose to race NRC and NCC rather than juniors so he upgraded and finished a semester of college - he is a Cat 1 and until Brandon came along this year the undisputed top junior - likely riding for Cannondale next year. Brandon did not upgrade although he has some 80 points (double). There are no points for Euro races. Its all too complicated and I don't totally get it. We parents all know who is best for what. They don't ask us.